Fluid process for treating rayon yarn packages



Aug. 19, 1958 F. E. CAMPBELL 2,347,750

FLUID PROCESS. FOR TREATING RAYON YARN PACKAGES Filed Sept. 15, 1953 YARN YARN YARN TREATMENT YARN TREATMENT HANDL'NG OPERATIONS HANDL'NG OPERATIONS OPERATIONS OPERATIONS I. WASH WASH CAK E 2. DESULFUR 3. WASH CAKE 4. DRY 2. LUBRICA TE CONE {5. OIL CREEL 3. WET OUT CREEL 4. STRETCH 5. DRY

6. LUBRICATE ANO wET OUT BEAM T: STRETCH a. DRY

BEAM I INVENTOR FL ETCHER EVANS CAMPBELL ATTORNEY United States Patent FLUID PROCESS FOR TREATING RAYON YARN PACKAGES Fletcher Evans Campbell, Wilmington, Del., assignor to E. I. du Pont de Nemours and Company, Wilmington, DeL, a corporation of Delaware Application September 15, 1953, Serial No. 380,161 11 Claims. (Cl. 28-72.6)

This invention relates to viscose rayon yarn. More particularly, it is concerned with a process for the production of a wound beam produced from bucket cakes of viscose rayon yarn.

It is an object of the present invention to provide a novel process for the production of a wound 'beam from bucket cakes of viscose rayon yarn.

It is a further object to provide a process wherein a wound beam is formed from bucket cakes of viscose rayon yarn without an intermediate coning operation.

A still further object is to provide such a process without intermediate drying and desulfnring of the washed cake.

These and other objects will become apparent in the course of the following specification and claims.

The invention will be more readily understood'by reference to the drawings.

Figure 1 illustrates diagrammatically the conventional yarn handling and yarn treatment operations in the pro duction of a beam of yarn from a cake of viscose rayon.

Figure 2 illustrates diagrammatically the various yarn handling and yarn treatment operations in the production of a beam of yarn from a cake of viscose rayon in accordance with the teachings of the present invention.

Comparing the processes illustrated in Figures 1 and 2, it will be noted that in the conventional process (as shown in Figure l) the viscose rayon yarn in the form of a cake is washed with water, desulfured with an aqueous solution of sodium carbonate, sodium silicate and sodium cyanide and then washed again with water to remove the desulfuring fluids. These liquids may be applied centrifugally to the cake. Thereafter, the cake is dried. The drying operation in the conventional process (designated yarn treatment step No. 4) is essential to attain the proper molecular alignment of the yarn. Failure to dry prior to conventional slashing causes the yarn to possess extremely poor fatigue resistance characteristics. After drying, the conventional process necessitates that the yarn be wound to form a cone prior to creeling. Attempts to creel from the dried cake results in excessive handling stops due to yarn breakage. Between the creel and the beam, the yarn is finished and wet out and thereafter stretched and dried. The parallel strands of lubricated and dried continuous filaments of viscose rayon are collected on the beam. The fatigue resistance of the resulting cords are generally within the range of about 12.1 to about 17.4 hours.

In accordance with the present invention as shown in Figure 2, the cake of viscose rayon yarn is first washed with water. At this point, an aqueous lubricating composition, to be described in more detail hereinafter, heated to a temperature above at least 50 C., is applied centrifugally to the cake under the impetus of centrifugal action, the cake being rotated at a rate within the limits of about 1000 to about 2400 R. P. M. The cake is then immediately creeled without the intermediate yarn treatment operations of desulfuring, washing or drying. Furthermore the yarn handling operation of coming is eliminated as is the oiling yarn treatment step that such coning necessitates. Between the creel and the beam, the yarn is wet out, stretched and dried. It is collected on the beam as parallel continuous filaments of viscose rayon yarn.

The following examples are presented by way of illustration and not by way of limitation.

A series of viscose rayon yarn cakes is prepared as follows: Various lots of viscose are spun into a bath containing 9% sulfuric acid, 23.0% sodium sulfate, and 3.5% zinc sulfate. The filament is hot dipped through a second bath containing the above ingredients diluted to less than 3% acid. It is then stretched to a tension of 0.75 gram per denier and thereafter delivered at a rate of 100 yards per minute to a 7-inch diameter spinning bucket rotating at 7000 R. P. M. The rate of viscose delivery is such as to produce a finished dry yarn of 1650 denier. The ultimate weight of the cake (based on air dry yarn) is approximately 3.5 pounds. The yarn cakes are centrifugally washed with water until acid free.

Part of the cakes from each lot are subjected to the process of the present invention. One embodiment consists in lubricating them with an oil in water emulsion of the composition:

Percent heated to C. and applied centrifugally at the rate of 2 gallons per minute for 4 minutes through a centrally located spray nozzle to the cake rotating in a bucket at 1700 R. P. M. The yarn while still in the form of a cake and while wet, is thereafter creeled, slashed and beamed. The slashing finish composition is substantially the same as thehot finish composition applied at the centrifuge.

A ribbon of cord so prepared is tested for fatigue resistance in accordance with the United States Rubber fatigue method. In this test the United States Rubber fatigue tester cyclically stetches and relaxes cords until they fail under the load applied. A selected minimum load is maintained by taking up slack during the relaxation part of each cycle by a ratchet mechanism. This tester fatigues a 30-inch specimen (made up of 15 cord ends) by subjecting it to a 1.7% (0.510 inch) stroke under a 0.14 g. p. d. load. The stroke frequency is 360 C. P. M. Atmospheric conditions in the tester are controlled at 65C. and 7% R. H. The number of hours required tobreak all of the 15 cords in the sample is called the United States Rubber fatigue. The particular results appear in Table I as column B.

The remaining cakes from each lot which have been collected in the spin potand centrifugally washed as described above, are creeled and beamed, while wet,'

3 resistance measurements are made on each lot. The results appear in Table I, column A. 'The average oil on the yarns in columns A and B are 0.54 and 0.58% respectively.

1 Temperature at which finish is applied centriiugally to the yarn in column B.

It will be apparent from a consideration of the figures in Table I that the improved and unexpected results of the present invention are not related to the amount of oil on the yarn. As is pointed out above, the conditions of the comparisons were so chosen that approximately the same amount of oil is on each sample of yarn regardless of its treatment procedure.

The nature of the hot centrifugally applied aqueous finishing composition is not critical. It must contain a yarn lubricant. Any of the usual petroleum oils, fats, waxes, soaps, or the like may be employed. Application in the form of an oil-in-water or water-in-oil emulsion is facilitated by the use of dispersing agents. The following compositions are typical of those which may be used:

Composition A 30parts olive oil earn a par s Bu 1) 011a e 01 v 45 parts mineral oil about Composition B QSQPartS lauric acid ][Diluted with water to an oil 140 parts triethanolamine content of about about 3%.

Composition C 29 parts sulphonated caster Diluted with water to an oil content of about 0.35%.

mineral oil 181.5 parts sorbitan monopal- Diluted with water to an, oil content of about 0.35%.

itate 1.8 parts triethanolamine Composition E 30 parts sorbitan monopalmi- Diluted with water to an oil.

ta e 35 parts sulphonated peanut about 035% Organic S03 being present to about 6.9% by weight.

The amount of finish remaining on the yarn at. the beam will vary, depending upon the concentration of the oil in the lubricating composition, the denier of the yarn, period of treatment, and the like. In general, it is desirable that the finish comprise about at least 0.40% of the weight of the finished yarn. Higher amounts may be applied without-deleterious effects. A concentration within the range of from about 0.40% to about 0.80% is satisfactory. When operating according to the process of the present invention, this quantity is deposited where the centrifugally applied lubricant contains from about 1% to about 2% finish, and is applied at a rate of from about 1 to about 5 gallons per minute for from about 2 to about minutes.

It is essential to the production of yarn of satisfactory quality that the centrifugally applied lubricant be warm sity of drying,

at the time the cake is treated. Temperatures as low as about 55 C. are satisfactory. It is preferred to operate within the range of from about 75 C. to about C. It is often convenient to add the lubricant at the boil. At temperatures below about 50 C. a loss in tensile strength of the yarn is observed. Furthermore other undesirable features are introduced such as staining of the yarn and loss of efficiency in carbon disulfide removal.

Optimum centrifugal speed for application of the heated lubricant lies between the ranges of about 1500 and about 2200 R. P. M. Outside of this range appreciable fatigue loss in the treated yarn is noted. The preferred speed is about 1700 R. P. M. Conventional equipment for the purpose, such as is described in United States Patent 2,527,663 is employed.

The increased eificiency of the present process over that conventionally employed is illustrated in the drawing. Figure 1 outlines the conventional yarn handling and yarn treatment operations while Figure 2 presents the corresponding information relative to the process of the present invention. In the conventional process (Figure 1) the yarn is subjected to four handling operations and eight treatment operations. In the process of the present invention (Figure 2) only three handling and five treatment operations are necessary. The centrifugal application of heated lubricant to the wet washed cake of yarn makes possible the direct creeling of the cake. Intermediate coning is unnecessary since the lubricant wet cake is creeled. When the cake is dried before creeling, coning is essential since plucks and snarls occur on unwinding of such a cake due to its deformation during the drying operation. Failure to dry when proceeding in the conventional manner of Figure 1 leads to a nonuniform yarn having extremely poor fatigue resistance properties. The present invention eliminates the necesa time and space consuming operation, without sacrifice of fatigue resistance and with the further advantage that the coning operation is rendered unnecessary.

In addition to the advantages outlined above it has .been found possible to eliminate the usual desulfuring and second wash yarn treatment operations of the conventional process when proceeding in accordance with the present invention. This is possible due to the cleansing action of the warm lubricant and also due to the fact that the yarn is handled wet and does not present the dust irritation problem to operators which is unbearable in conventional operation in the absence of highly efficicnt desulfuring procedures. While a somewhat higher than usual residual sulfur is experienced on the beamed yarn, it is not high enough to be objectionable and indeed is beneficial in tire yarn where subsequent vulcanization is practiced.

In a typical preparation of a beam of yarn, wet cakes which have been treated with centrifugally applied heated lubricant as described previously, are creeled to provide a beam of 200 ends. The yarn is slashed between the creel and the beam by wetting out the traveling warp with a composition essentially the same as that of the centrifugally applied lubricant. It is thereafter stretched about 9% by imposing a tension of about grams. The warp is dried over drums to a final moisture content of about 6%. About 1000 pounds of wound yarn results.

It is preferred to employ the same composition in the slasher as is used in the lubrication by centrifugal action. Where such is the case, the slashing is a wetting out rather than a lubrication, there being essentially no pickup of lubricant by the warp in the slasher. This Vimproves efiiciency in operation since the lubricant concentration of the slasher bath is more readily controlled.

This application is a continuation-in-part of Serial Number 142,089 filed February 2, 1950 and now abandoned.

Many other modifications within the scope of the present invention will be obvious to those skilled in the art without departure from the inventive concept.

What is claimed is:

1. A process for producing a beam of yarn from a bucket cake of viscose rayon yarn which comprises centrifugally applying an aqueous lubricating composition, heated to a temperature of at least 50 C., to a wet cake of washed viscose rayon yarn rotating at a rate within the limits of from about 1000 R. P. M. to 2400 R. P. M., and thereafter directly creeling the lubricated wet bucket cake, wetting out the resultant warp, followed by stretching, drying and beaming the parallel continuous filaments.

2. The process of claim 1 wherein the speed of the rotating cake is from about 1500 R. P. M. to about 2200 R. P. M.

3. The process of claim 1 wherein the wetting out composition is the same as the lubricating composition.

4. The process of claim 1 wherein the aqueous lubricating composition is heated to a temperature of. from about 70 C. to about 95 C.

5. A process for producing a beam of yarn from spun viscose rayon yarn which comprises subjecting the said yarn to the yarn handling operations in the order recited, and consisting of (a) collecting the said yarn centrifugally in the form of a cake, (b) creeling the said yarn and (c) thereafter winding the said yarn upon a beam, the said yarn handling operations being performed in conjunction with yarn treatment operations in the order recited and consisting of (l) a water wash of the centn'fugally collected cake of yarn until acid free, followed by (2) centrifugal application to the wet, washed cake, rotating within the limits of from about 1000 R. P. M. to 2400 R. P. M., of an aqueous lubricating composition, heated to a temperature of at least 50 C., (3) wetting out the traveling warp between the creel and the beam, (4)

stretching the yarn after the aforementioned wetting out of the said Warp and (5) drying the yarn after aforementioned wetting out and stretching operations.

6. The process of claim 5 wherein the aqueous lubricating composition of yarn treatment operation (2) is an emulsion comprising water, a yarn lubricant and a dis persing agent and is applied at a temperature within a range of from about C. to about C. to a wet washed cake rotating at about 1700 R. P. M.

7. The process of claim 5 wherein yarn treatment operation (3), namely, wetting out of the traveling warp between the creel and the beam is performed with the lubricating composition of yarn treatment operation (2).

8. The process of claim 5 wherein the yarn is stretched about 9% in yarn treatment operation 4).

9. The process of claim 5 wherein the yarn is dried to a moisture content of about 6% in yarn treatment operation (5).

10. The process of claim 5 wherein the yarn is a tire cord yarn.

11. The process of claim 6 wherein the aqueous lubricating composition is applied at a rate of 2 gallons per minute for 4 minutes.

References Cited in the file of this patent UNITED STATES PATENTS 1,770,412 Leuchs July 15, 1930 1,770,729 Borzykowski July 15, 1930 1,779,831 Stokes Oct. 28, 1930 1,979,929 Banigan Nov. 6, 1934 2,300,254 Jackson Oct. 27, 1942 2,453,332 Millhiser Nov. 9, 1948 2,527,663 Thompson Oct. 31, 1950 2,549,014 Romeyn Apr. 17, 1951 

1. A PROCESS FOR PRODUCING A BEAM OF YARN FROM A BUCKET CAKE OF VISCOSE RAYON YARN WHICH COMPRISES CENTRIFUGALLY APPLYING AN AQUEOUS LIBRICATING COMPOSITION, HEATED TO A TEMPERATURE OF AT LEAST 50*C., TO A WET CAKE OF WASHED VISCOSE RAYON YARN ROTATING AT A RATE WITHIN TH LIMITS OF FROM ABOUT 1000 R.P.M. TO 2400 R.P.M., AND THEREAFTER DIRECTELY CREELING THE LUBRICATED WET BUCKET CAKE, WETTING OUT THE RESULTANT WARP, FOLLOWED BY STRETCH, ING, DRYING AND BEAMING THE PARALLEL CONTINUOUS FILAMENTS. 